Expose IANA time zone version

.eslintignore

@@ -1,3 +1,4 @@
 dist/
 raw-time-zones.json
 time-zones-names.json
+metadata.json

.prettierignore

@@ -13,3 +13,4 @@
 /dist/
 time-zones-names.json
 raw-time-zones.json
+metadata.json

README.md

@@ -22,7 +22,7 @@ npm add @vvo/tzdb
 Usage:
 
 ```js
-import { getTimeZones, rawTimeZones, timeZonesNames, abbreviations } from "@vvo/tzdb";
+import { getTimeZones, rawTimeZones, timeZonesNames, abbreviations, metadata } from "@vvo/tzdb";
 ```
 
 ## API
@@ -167,6 +167,16 @@ This is an object mapping timezone abbreviations to their full forms:
 
 **Caution:** Although abbreviations can be easy to lookup, they can be misleading. For example: CST can refer to Central Standard Time (-06.00 UTC), China Standard Time (+06.00 UTC) or Cuba Standard Time (-05.00 UTC). And abbreviation full forms don't directly map to any property in the time zone objects returned by `rawTimeZones` or `getTimeZones()`.
 
+### metadata
+
+This is an object containing metadata about the package:
+
+```js
+{
+  ianaTzVersion: "2025b", // The IANA time zone database version
+}
+```
+
 ## Notes
 
 - We provide two cities when grouping happens, ranked by population

generate.js

@@ -8,7 +8,7 @@ import unzipper from "unzipper";
 import got from "got";
 import { DateTime } from "luxon";
 import { orderBy, uniq } from "lodash";
-import tzdata from "tzdata";
+import * as tzdata from "tzdata";
 
 import abbreviations from "./abbreviations.json";
 import formatTimeZone from "./lib/formatTimeZone.js";
@@ -18,6 +18,14 @@ const timeZonesLinks = Object.entries(tzdata.zones).filter(([, value]) => {
 });
 
 async function run() {
+  // Validate time zone versions match
+  if (process.versions.tz !== tzdata.version) {
+    console.error(
+      `Time zone versions do not match\n  Node tz version: ${process.versions.tz}\n  tzdata version: ${tzdata.version}`,
+    );
+    process.exit(1);
+  }
+
   const continents = {
     AF: "Africa",
     AS: "Asia",
@@ -312,6 +320,11 @@ async function run() {
       ]),
     ).replace(/},/g, "},\n"),
   );
+
+  fs.writeFileSync(
+    path.join(__dirname, "metadata.json"),
+    JSON.stringify({ ianaTzVersion: tzdata.version }),
+  );
 }
 
 run().catch((error) => {

index.d.ts

@@ -23,6 +23,11 @@ interface TimeZoneOptions {
   includeUtc?: boolean;
 }
 
+interface Metadata {
+  ianaTzVersion: string;
+}
+
 export const rawTimeZones: RawTimeZone[];
 export const timeZonesNames: TimeZoneName[];
 export function getTimeZones(opts?: TimeZoneOptions): TimeZone[];
+export const metadata: Metadata;

lib/index.js

@@ -2,3 +2,4 @@ export { default as rawTimeZones } from "../raw-time-zones.json";
 export { default as timeZonesNames } from "../time-zones-names.json";
 export { default as getTimeZones } from "./getTimeZones.js";
 export { default as abbreviations } from "../abbreviations.json";
+export { default as metadata } from "../metadata.json";

metadata.json

@@ -0,0 +1 @@
+{"ianaTzVersion":"2025b"}

package.json

@@ -27,6 +27,7 @@
     "time-zones-names.json",
     "abbreviations.json",
     "raw-time-zones.json",
+    "metadata.json",
     "LICENSE",
     "README.md",
     "index.d.ts"
@@ -117,7 +118,7 @@
     "semantic-release": "18.0.1",
     "semantic-release-cli": "5.4.6",
     "sort-keys": "4.2.0",
-    "tzdata": "1.0.45",
+    "tzdata": "1.0.46",
     "unzipper": "0.12.3"
   },
   "publishConfig": {